Prompted by an alert note posted today by David Cardeñosa on [Comets-ml] about the unusual aspect of 217P/LINEAR he recorded in his images of this comet obtained on 2009, Aug 22.1, we performed some follow-up about 217P remotely, through a 0-25-m, f/3.4 reflector + CCD (near Mayhill, NM).
Co-adding of 12 unfiltered exposures, 120 seconds each, obtained on 2009, Aug. 22.4, confirms the presence of a highly structured coma. The central condensation appears sharp, and elongated in a West-East direction. A spiralling arclet about 1.5 arcmin long is emanating from the central condensation in clockwise direction.
Arclet are temporary phenomena in the cometary coma that are related with fragmentation events of the nucleus
We notice the presence of two distinct tails: one about 1.8 arcmin long in PA 245 deg, and a second one, about 2 arcmin long in PA 236 deg.
Our image is available here:
We notice that the current aspect of 217P, is striking similar to that of comet 73P-fragment B, at the time of its repeated outburst/splitting events occured in May 2006, e.g.:
Our Team recovered this comet on March 2009.
by Ernesto Guido & Giovanni Sostero